连续台风时期香港区域的水汽变化分析     

周苏娅  闻德保  梅登奎 《大地测量与地球动力学》2020,40(1):82-86

利用香港卫星定位参考站网GNSS观测数据,提取强热带风暴"塔拉斯"与热带风暴"洛克"影响期间各测站天顶方向对流层延迟,反演香港区域大气可降水量;根据香港区域49个天文台气象站提供的实测降雨量数据,分析大气可降水量与实际降雨量的相关性,以及两次台风对香港区域水汽时空分布的不同影响。结果表明,大气可降水量在台风影响前期均上升,在大量降雨后回落,但在连续台风的间歇期间,仍高于台风来临前的水平;水汽累积是大量降雨的前提条件,当水汽累积量相近时,水汽累积时长与累积降雨量呈正相关;台风期间大气可降水量值超过65 mm的区域面积与台风等级相关,台风路径对局部水汽分布有一定的影响。  相似文献   

The European vision for oceans and seas—Social and political dimensions of the Green Paper on Maritime Policy for the EU     

Juan Luis Suárez de Vivero 《Marine Policy》2007

The EU Green Paper on Maritime Policy is the European response to the new generation of ocean strategies based on science, technology and innovation aimed at new objectives, such as the strengthening of security and access to new resources. The European character of the proposal is found in the presence of social, cultural and historical elements, what is called the “European vision”. The viability of a European vision of the oceans and the idea of maritime empire as an extension of the current concept of empire within the general context of emerging ocean strategies are the elements offered up for debate on this European Union initiative.  相似文献   

National ocean policy—new opportunities for Malaysian ocean development     

Abdul Hamid Saharuddin   《Marine Policy》2001,25(6)

Being a littoral state, Malaysian maritime sectors provide the basis for the growth and development of marine-related activities. As the country enters the new millennium along with the ‘2020 Vision’ which serves as the basic template against which the economic performance of these sectors should be judged, it poses a new challenge for Malaysia in developing these sectors. This paper attempts to address three basic issues: Firstly, is there any national ocean policy in place? Secondly, are the maritime sectors adequately organized to play an important role in achieving the objectives? Thirdly, what are the opportunities available in developing the ocean?It can be seen that existing policies to develop comprehensive ocean governance have not received the full attention they deserve. Organizational structures governing the ocean for implementing national policies are well in place but in a fragmented and uncoordinated fashion. As a result, sectoral and intersectoral management problems were created such as multiple-use conflicts, overlapping of jurisdiction and duplication of efforts. Environmental problems have also not been properly addressed. A few sectors have been identified as offering opportunities to further develop the Malaysian maritime areas. Among these are marine education and human resources development, marine tourism and the seafood industry.  相似文献   

黄海北部长山群岛海洋农牧化分区探讨   总被引：7，自引：0，他引：7  

张耀光 《地理学报》1991,46(1):47-56

本文采用主成分-聚类分析等定量方法,并通过对长山群岛海域的资源、环境、生产条件等的相似性和差异性分析,将其划分为三个海洋农牧化区域,为海水养殖业的合理布局提供科学依据。  相似文献   

青藏高原地面-对流层系统的能量收支   总被引：3，自引：3，他引：3  

沈志宝  成天涛  王可丽 《高原气象》2002,21(6):546-551

利用CCM3中的辐射模式CRM，计算了1月和7月地－气系统、地面－对流层系统和地面辐射能收支，研究了青藏高原地面－对流层系统辐射能收支的冬、夏季节特征及其与地面和地－气系统辐射能收支的关系，并与东部平原地区和高原北侧干旱地区比较。文中还讨论了云和高原冬季地面积雪对辐射能收支的影响，比较了大气辐射加热和地面感热通量对夏季高原对流层大气加热的贡献。  相似文献   

On the Spatial Distribution and Seasonal Variation of Lower-Troposphere Ozone over Europe     

H. E. Scheel  H. Areskoug  H. Geiss  B. Gomiscek  K. Granby  L. Haszpra  L. Klasinc  D. Kley  T. Laurila  A. Lindskog  M. Roemer  R. Schmitt  P. Simmonds  S. Solberg  G. Toupance 《Journal of Atmospheric Chemistry》1997,28(1-3):11-28

Surface ozone data from 25 Europeanlow-altitude sites and mountain sites located between79°N and 28°N were studied. The analysiscovered the time period March 1989–February 1993.Average summer and winter O₃ concentrations inthe boundary layer over the continent gave rise togradients that were strongest in the north-west tosouth-east direction and west-east direction, respectively. WintertimeO₃ ranged from 19 to 27 ppbover the continent, compared to about 32 ppb at thewestern border, while for summer the continentalO₃ values ranged between 39 and 56 ppb and theoceanic mixing ratios were around 37 ppb. In the lowerfree troposphere average wintertime O₃ mixingratios were around 38 ppb, with only an 8 ppbdifference between 28°N and 79°N. For summerthe average O₃ levels decreased from about 55 ppbover Central Europe to 32 ppb at 79°N. Inaddition, O₃ and O_x(= O₃ + NO₂)in polluted and clean air were compared. Theamplitudes of the seasonal ozone variations increasedin the north-west to south-east direction, while thetime of the annual maximum was shifted from spring (atthe northerly sites) to late summer (at sites inAustria and Hungary), which reflected the contributionof photochemical ozone production in the lower partsof the troposphere.  相似文献   

Upper-Tropospheric Environment–Tropical Cyclone Interactions over the Western North Pacific: A Statistical Study     

Yu-Kun QIAN  Chang-Xia LIANG  Zhuojian YUAN  Shiqiu PENG  Junjie WU  Sihua WANG 《大气科学进展》2016,33(5):614-631

Based on 25-year(1987–2011) tropical cyclone(TC) best track data, a statistical study was carried out to investigate the basic features of upper-tropospheric TC–environment interactions over the western North Pacific. Interaction was defined as the absolute value of eddy momentum flux convergence(EFC) exceeding 10 m s~(-1)d~(-1). Based on this definition, it was found that 18% of all six-hourly TC samples experienced interaction. Extreme interaction cases showed that EFC can reach~120 m s~(-1)d~(-1) during the extratropical-cyclone(EC) stage, an order of magnitude larger than reported in previous studies.Composite analysis showed that positive interactions are characterized by a double-jet flow pattern, rather than the traditional trough pattern, because it is the jets that bring in large EFC from the upper-level environment to the TC center. The role of the outflow jet is also enhanced by relatively low inertial stability, as compared to the inflow jet. Among several environmental factors, it was found that extremely large EFC is usually accompanied by high inertial stability, low SST and strong vertical wind shear(VWS). Thus, the positive effect of EFC is cancelled by their negative effects. Only those samples during the EC stage, whose intensities were less dependent on VWS and the underlying SST, could survive in extremely large EFC environments, or even re-intensify. For classical TCs(not in the EC stage), it was found that environments with a moderate EFC value generally below ~25 m s~(-1)d~(-1) are more favorable for a TC's intensification than those with extremely large EFC.  相似文献   

中国东部高空颠簸时空分布特征及其与热带中东太平洋海温的关系   总被引：1，自引：0，他引：1  

阿利曼  王君  冯锦明  李秀连 《大气科学》2016,40(5):1073-1088

本文利用1979～2014年NCEP-DOE日平均再分析资料和中国区域2375份航空器空中颠簸报告资料,研究中国东部区域高空颠簸的时空分布特征及其与热带中东太平洋海温异常（简称“海温异常”;空间范围:5°S～5°N,120°～170°W）的关系以及产生这种关系的可能原因。结果表明:中国东部地区高空颠簸与东亚副热带西风急流之间存在显著时空相关关系,其原因是高空纬向风引起的垂直风切变是构成高空颠簸时空分布的主导因素。中国东部夏季高空颠簸与海温异常存在正相关关系;冬季呈现南北两个正负相关区:以30°N为界,北部区域存在显著的负相关,南部区存在显著的正相关,在30°N急流轴附近区域无显著相关关系。海温异常影响中国高空颠簸时空分布的可能原因是海温变化引起对流层高层温度出现异常,进而影响温度的经向梯度,导致东亚副热带西风急流强度和位置出现异常（夏季,急流轴南侧出现西风异常;冬季,急流轴北侧出现东风异常,南侧出现西风异常）。高空纬向风的变化导致纬向风的垂直梯度和经向梯度出现异常,最终影响高空颠簸的时空分布特征。对流层高层温度的异常变化可能是由与热带海温异常相关的平流层水汽变化所引起。  相似文献   

Ocean governance and maritime security in a placeful environment: The case of the European Union     

《Marine Policy》2016

Adopting a critical geopolitics approach that accounts for the mutually reinforcing link between geo-informed narratives and projection practices, this article proposes that ocean governance and maritime security have translated into states' and regional organisations' increasing control over maritime spaces. This leads to a certain territorialisation of the sea, not so much from a sovereignty and jurisdictional perspective but from a functional and normative perspective. The article starts by discussing the ways oceans have been represented and shows that they are far from a placeless void, both in practice and in discourse. The article then frames the analysis of ocean governance and maritime security within critical geopolitics, and elaborates on the case of the European Union's narrative and practice. It concludes on the mutually reinforcing link between discourse and practice in the field of ocean governance and maritime security in general, and on the consequences for the EU in particular. Scholars working on ocean governance and maritime security are encouraged to challenge the traditional view that oceans are placeless.  相似文献   

Science and Technology of Delimitation of Continental Shelf and Its Application in Maritime Silk Road Cooperation*     

Qiuci Sun  Yinxia Fang  Jiabiao Li 《地球科学进展》2018,33(12):1215-1222

Delimitation of the continental shelf is an emerging interdisciplinary discipline in the field of international marine science and technology. It uses the scientific and technological means to expand the jurisdiction of coastal states based on the international rules of the 《United Nations Convention on the Law of the Sea》. Therefore, it is related to the marine sovereignty rights and interests of a country and also a hot topic of science and technology that all countries have competed to develop. China has launched the research in this field simultaneously with the world's maritime powers, and formed its innovative advantages in such aspects as geological models, detection techniques and delimitation systems in the delimitation of continental shelf, which have become the brand new ties for China's cooperation with foreign countries in marine science and technology, and also the important field in the maritime silk road cooperation in the 21^st century. This paper introduced the basic principles and methods in the delimitation of continental shelf beyond 200 nautical miles (370 km), progress in the delimitation of the global continental shelf, and China's innovative science and technology as well as its application in maritime Silk Road cooperation, and provided the prospect of the future scientific and technological cooperation with foreign countries and development in this filed. And it was suggested China should develop the scientific and technological cooperation on the delimitation of the continental shelf along the Silk Road, promote the scientific and technological development of the delimitation of the continental shelf in China, and enhance China's influence and voice in international ocean affairs.  相似文献